by
Mohammed Ahmed , Sr.Project Engineer , Saudi Electricity Company
It depends.
Concrete gains strength at a non-linear rate (Initially high, later low) and at any stage of time, as long as its strength > strength requirements, you don't need any propping.
Mostly, during construction, the loads acting on the beams/slabs are
1) Self weight
2) Construction load (or)
3) Weight of upper floor (from the props !) but this is a separate load case
